How do you handle this FSBO objection when they say they’ve already sold their home?

1. Congratulate them. First, take it at face value and congratulate them. And then ask them a few questions (Have they signed the offer? Has the earnest money been deposited?). Never sound skeptical or make the FSBO wrong. 
2. Offer help. Ask if they have any questions or if they need help going through the process of making sure that the transaction closes. You can offer your services for a reduced commission (1 or 2%). 
3. Don’t buy their story. Don’t believe that they’ve actually already sold the property. They’re inexperienced with the entire process, so the deal could still fall through. 
4. Follow up every week. Don’t worry about being annoying or pushy. Call them to simply touch base and find out how things are going and if there’s anything you can do to help.
5. Come to the rescue. There’s a good chance that the transaction won’t close, so be ready to come to the FSBO’s rescue. Because you’ve already established credibility and trust with them, they now feel that you’re on their side and that you’re genuinely willing to help.